A number of different pumps of the aforementioned type have been patented and commercialized in the prior art for the purpose of pumping water from a body of water on which the pump is deployed. In their basic form, each such pump comprise an engine or motor mounted atop a pump housing containing an impeller that is rotatably driven by a vertical drive shaft from the engine. An inlet opening of the pump housing via which liquid is drawn into the pump from the body of water is situated at a bottom end of the pump housing, and an outlet through which the liquid is discharged is oriented generally radially of the vertical rotational axis of the impeller.
Such pumps are useful in disaster relief applications (e.g. removing flood waters), oilfield applications, construction applications, forestry/firefighting applications, and agricultural applications such as draining of sloughs, supplying of water to livestock, irrigating of farmland or removal of water from flooded areas, although other industries such as forestry and construction can likewise benefit from use of such pumps.
Examples of prior art self-priming floating pumps are found in U.S. Pat. No. 1,920,371 of Franke, U.S. Pat. No. 3,461,807 of Morrison, U.S. Pat. No. 3,400,664 of Kingsep, U.S. Pat. Nos. 3,470,822 and 3,612,721 of Evans et al., U.S. Pat. No. 3,619,075 of Chmela et al., U.S. Pat. No. 3,762,557 of Tudor et al., and U.S. Pat. No. 4,553,902 of Eberhardt.
Among these prior pump designs, it is known to use a generally pan-shaped inlet sieve with a circular bottom wall and a perforated circumferential wall upstanding from the bottom wall around the perimeter thereof to prevent water-carried debris from entering the pump inlet and causing damage to the pump. The top of the circumferential wall is attached to the underside of the pump body around the central inlet opening that feeds into the impeller chamber, and the openings in the circumferential wall allow water to reach the pump inlet but are sized to prevent entry of larger debris.
As water is drawn into the sieve in different radial directions through the circumferential wall, impact of these different directional flows with one another beneath the pump inlet many introduce unwanted turbulence that interferes with smooth intake by the pump. In addition, notable energy may be consumed by relying on the pump as the sole tool for redirecting the horizontally-inflowing water streams upwardly into the impeller chamber of the pump.
Applicant has developed a unique inlet sieve design to address these issues to provide smoother and less energy intensive water intake, and thereby improve pump performance and efficiency.